265/588 patients had a crucial CT examination for diagnosis so CT was considered appropriate according Iguide [3].
323/588 patients had a diagnosis in witch the CT scan could be considered possibly appropriate for Iguide.
Of these,138 had an inappropriate CT request according I guide [3];187 instead,
despite CT has not confirmed the proposed diagnostic for referral,
had an appropriate request based on the clinical suspicion and guidelines [3].
We have researched the most appropriate diagnostic method for 161/588 patients with more frequently pathologies (Fig.1) (i.e.uncomplicated appendicitis,
urolithiasis,
Crohn’s disease,
cholelithiasis and benign female adnexal masses),
according to the guidelines [3] based on ACR appropriateness criteria and compared the results with our database.
The appropriateness ranking scale is an ordinal scale that uses numbers from 1-9,
group in to three categories: usually not appropriate :1,
2,
or 3 ; may be appropriate : 4,
5,
or 6 ; usually appropriate: 7,
8,
or 9 .
We have also recorded the mean CTDIvol and its standard deviation for each group,
and the ED.
ED was calculated with the 75th percentile of the total DLP multiplied by 0.016 which is the tissue sensitivity factors.
The overall analysis of the 161 patients whose diagnosis could be potentially performed through CT (i.e.
uncomplicated appendicitis,
urolithiasis,
Crohn’s disease,
cholelithiasis or adnexal masses),
showed that only in 37,9% of the patients a US study had been performed prior to CT.
In the Fig.2,
it is possible to find the values of appropriateness and diagnostic validity expressed with the Consult Appropriate Use Criteria (AUC) score from 0 to 9(for each group and for both sexes) [1-2].
In the Fig.3 and Fig.4,
we have reported the values of CTDI vol and ED for overall performed CT exams and for the diseases considered for our study .